From: E.braswell <BRASS@UCONNVM.UCONN.EDU>
  To  : RASMB@bbri.org
  Date: Thu, 24 Jun 99 23:33:41 EDT

Small Mol. Correection

Karen and all--In my earlier message I mentioned a"Trout's" rule but later
tought that fishy and remembered "Traub(e?)'s rule...much better!  I bbelieve
it is mentioned in a reference in Tom Laue's article in the Harding book.
As for understanding charge non-ideality,Walter why not go the horse's mouth?
H. Eisenberg, he will scare religion into you about the proper ways to treat
charge effects. Unfortunately you must have a highly precise density meter,
and loads of time and patience.  I do think it possible to get good fits but
bad values for an ideal model even if it is highly charged.
if the sigma you are spining at is not very high.  To really
test the hypothesis you should be spining these molecules  at least 40k
and the column ht should be about 5-6 mm.  This will take a long time to reach
equil., because of the long column ht.  But even with this treatment you might
get equally good fits with either model.. Try floating B after you get a good
fit with B=0.  I'll bet the results will be correllated.     Emory

Emory H. Braswell
Professor of Biophysics and Head,
National Analytical Ultracentrifugation Facility
U-125
University of Connecticut
Storrs, CT 06269-3125
TEL 860 486 5032
FAX         5005
E.BRASWELL@UCONN.EDU